Mutations in this gene lead to tuberous sclerosis. Its gene product is believed to be a tumor suppressor and is able to stimulate specific GTPases. The protein associates with hamartin in a cytosolic complex, possibly acting as a chaperone for hamartin. Alternative splicing results in multiple transcript variants encoding different isoforms of the protein.[1] Together with tuberous sclerosis, mutations in TSC2 can cause Lymphangioleiomyomatosis, a disease caused by the enlargement of tissue in the lungs, creating cysts and tumours and causing difficulty breathing. Because Tuberin regulates cell size, along with the protein Hamartin coded by the gene TSC1, mutations to these genes may prevent the control of cell growth in the lungs of individuals.[2]
Signaling Pathways
Pharmacological inhibition of ERK1/2 restores GSK3β activity and protein synthesis levels in a model of tuberous sclerosis.[3]
Interactions
TSC2 functions within a multi-protein complex knowns as the TSC complex which consists of the core proteins TSC2, TSC1,[4][5] and TBC1D7.
TSC2 has been reported to interact with several other proteins that are not a part of the TSC complex including:
↑Pal R, Bondar VV, Adamski CJ, Rodney GG, Sardiello M (2017). "Inhibition of ERK1/2 Restores GSK3β Activity and Protein Synthesis Levels in a Model of Tuberous Sclerosis". Sci. Rep. 7 (1): 4174. doi:10.1038/s41598-017-04528-5. PMID28646232.
↑ 9.09.1Cao Y, Kamioka Y, Yokoi N, Kobayashi T, Hino O, Onodera M, Mochizuki N, Nakae J (2006). "Interaction of FoxO1 and TSC2 induces insulin resistance through activation of the mammalian target of rapamycin/p70 S6K pathway". J. Biol. Chem. 281 (52): 40242–51. doi:10.1074/jbc.M608116200. PMID17077083.
↑Inoki K, Ouyang H, Zhu T, Lindvall C, Wang Y, Zhang X, Yang Q, Bennett C, Harada Y, Stankunas K, Wang CY, He X, MacDougald OA, You M, Williams BO, Guan KL (2006). "TSC2 integrates Wnt and energy signals via a coordinated phosphorylation by AMPK and GSK3 to regulate cell growth". Cell. 126 (5): 955–68. doi:10.1016/j.cell.2006.06.055. PMID16959574.
↑Ma L, Chen Z, Erdjument-Bromage H, Tempst P, Pandolfi PP (2005). "Phosphorylation and functional inactivation of TSC2 by Erk implications for tuberous sclerosis and cancer pathogenesis". Cell. 121 (2): 179–93. doi:10.1016/j.cell.2005.02.031. PMID15851026.
↑Gan B, Yoo Y, Guan JL (2006). "Association of focal adhesion kinase with tuberous sclerosis complex 2 in the regulation of s6 kinase activation and cell growth". J. Biol. Chem. 281 (49): 37321–9. doi:10.1074/jbc.M605241200. PMID17043358.
↑Murthy V, Han S, Beauchamp RL, Smith N, Haddad LA, Ito N, Ramesh V (2004). "Pam and its ortholog highwire interact with and may negatively regulate the TSC1.TSC2 complex". J. Biol. Chem. 279 (2): 1351–8. doi:10.1074/jbc.M310208200. PMID14559897.
↑Inoki K, Zhu T, Guan KL (2003). "TSC2 mediates cellular energy response to control cell growth and survival". Cell. 115 (5): 577–90. doi:10.1016/S0092-8674(03)00929-2. PMID14651849.
↑Shaw RJ, Bardeesy N, Manning BD, Lopez L, Kosmatka M, DePinho RA, Cantley LC (2004). "The LKB1 tumor suppressor negatively regulates mTOR signaling". Cancer Cell. 6 (1): 91–9. doi:10.1016/j.ccr.2004.06.007. PMID15261145.
↑ 16.016.1Castro AF, Rebhun JF, Clark GJ, Quilliam LA (2003). "Rheb binds tuberous sclerosis complex 2 (TSC2) and promotes S6 kinase activation in a rapamycin- and farnesylation-dependent manner". J. Biol. Chem. 278 (35): 32493–6. doi:10.1074/jbc.C300226200. PMID12842888.
↑Yamamoto Y, Jones KA, Mak BC, Muehlenbachs A, Yeung RS (2002). "Multicompartmental distribution of the tuberous sclerosis gene products, hamartin and tuberin". Arch. Biochem. Biophys. 404 (2): 210–7. doi:10.1016/S0003-9861(02)00300-4. PMID12147258.
↑Garami A, Zwartkruis FJ, Nobukuni T, Joaquin M, Roccio M, Stocker H, Kozma SC, Hafen E, Bos JL, Thomas G (2003). "Insulin activation of Rheb, a mediator of mTOR/S6K/4E-BP signaling, is inhibited by TSC1 and 2". Mol. Cell. 11 (6): 1457–66. doi:10.1016/S1097-2765(03)00220-X. PMID12820960.
↑Zhang Y, Gao X, Saucedo LJ, Ru B, Edgar BA, Pan D (2003). "Rheb is a direct target of the tuberous sclerosis tumour suppressor proteins". Nat. Cell Biol. 5 (6): 578–81. doi:10.1038/ncb999. PMID12771962.
↑Long X, Lin Y, Ortiz-Vega S, Yonezawa K, Avruch J (2005). "Rheb binds and regulates the mTOR kinase". Curr. Biol. 15 (8): 702–13. doi:10.1016/j.cub.2005.02.053. PMID15854902.
↑Lu Z, Hu X, Li Y, Zheng L, Zhou Y, Jiang H, Ning T, Basang Z, Zhang C, Ke Y (2004). "Human papillomavirus 16 E6 oncoprotein interferences with insulin signaling pathway by binding to tuberin". J. Biol. Chem. 279 (34): 35664–70. doi:10.1074/jbc.M403385200. PMID15175323.
↑Zheng L, Ding H, Lu Z, Li Y, Pan Y, Ning T, Ke Y (2008). "E3 ubiquitin ligase E6AP-mediated TSC2 turnover in the presence and absence of HPV16 E6". Genes Cells. 13 (3): 285–94. doi:10.1111/j.1365-2443.2008.01162.x. PMID18298802.
↑Nellist M, Goedbloed MA, de Winter C, Verhaaf B, Jankie A, Reuser AJ, van den Ouweland AM, van der Sluijs P, Halley DJ (2002). "Identification and characterization of the interaction between tuberin and 14-3-3zeta". J. Biol. Chem. 277 (42): 39417–24. doi:10.1074/jbc.M204802200. PMID12176984.
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Ramesh V (2004). "Aspects of tuberous sclerosis complex (TSC) protein function in the brain". Biochem. Soc. Trans. 31 (Pt 3): 579–83. doi:10.1042/BST0310579. PMID12773159.
Knowles MA, Hornigold N, Pitt E (2004). "Tuberous sclerosis complex (TSC) gene involvement in sporadic tumours". Biochem. Soc. Trans. 31 (Pt 3): 597–602. doi:10.1042/BST0310597. PMID12773163.
Ellisen LW (2007). "Growth control under stress: mTOR regulation through the REDD1-TSC pathway". Cell Cycle. 4 (11): 1500–02. doi:10.4161/cc.4.11.2139. PMID16258273.
Jozwiak J, Jozwiak S (2007). "Giant cells: contradiction to two-hit model of tuber formation?". Cell. Mol. Neurobiol. 27 (2): 251–61. doi:10.1007/s10571-006-9106-0. PMID16897363.
Cai SL, Walker CL (2007). "TSC2, a key player in tumor suppression and cystic kidney disease". Nephrol. Ther. 2 Suppl 2: S119–22. PMID17373211.
Urban T (2007). "[Pulmonary lymphangioleiomyomatosis with or without tuberous sclerosis]". Revue des maladies respiratoires. 24 (6): 725–40. doi:10.1016/S0761-8425(07)91147-X. PMID17632432.